CN2437085Y - Hands-free handset for mobile phone for car - Google Patents

Abstract

The utility model relates to a hands-free handset for a mobile phone in a car, which comprises a mobile phone holder, a hands-free handset host arranged behind the holder, an interface box plugged between the mobile phone and the hands-free handset host, a microphone and a speaker, and the hands-free handset host further comprises a microphone noise suppression circuit, a sound amplifier and a charging circuit. By matching interface boxes of different specifications, it can be suitable for connecting various mobile phones to each other.

Description

Hands-free handset for mobile phone for car

The utility model relates to a hands-free handset for a mobile phone for a vehicle, especially suitable for a mobile vehicle, so that the mobile phone can be used for talking without being held, so as to solve the inconvenience and trouble of talking when the vehicle is moving. Use the speakerphone on your mobile phone.

The current mobile phone hands-free handset for cars can not only charge the mobile phone to avoid the problem of power shortage, but also has the function of sending and amplifying incoming calls through the hands-free handset, so as to solve the inconvenience and inconvenience of answering the mobile phone while driving. Derived from the danger, it is generally loved by consumers. However, with the existing hands-free handset products on the market, in order to cooperate with different mobile phone models, brands and different interface specifications, various special-purpose hands-free handsets are designed. Replacing or purchasing the corresponding car speakerphone at the same time has the disadvantage of being too wasteful. Moreover, the most common problem with speakerphone calls is the phenomenon of call echo, which leads to unclear signals and poor call quality. Therefore, for the above problem, it is necessary to improve it.

The main purpose of the utility model is to provide a hands-free handset for a mobile phone for a vehicle without replacing the hands-free handset host.

The second object of the present invention is to provide a hands-free hands-free handset for a mobile phone for a vehicle that can solve the echo problem of the hands-free handset microphone and improve the communication quality of the hands-free handset.

The purpose of this utility model is achieved through the following technical solutions:

A hands-free handset for a mobile phone for a vehicle, comprising a mobile phone holder, a hands-free receiver set behind the holder, a microphone and a speaker plugged into the hands-free receiver, the hands-free receiver is provided with an interface socket, The sound amplifier and the charging circuit are characterized in that: an interface box is set between the hands-free handset socket of the mobile phone and the interface socket of the hands-free handset host, and the interface box consists of an interface plug that can be plugged into the interface socket, an interface plug that can be connected to the mobile phone The hands-free handset socket is composed of an adapter, the interface plug and the adapter are connected by wiring, resistors, and capacitors; a noise suppression circuit is installed in the hands-free handset host, which is composed of a buffer and connected to the microphone. The output end of the noise suppression circuit is transferred to the hands-free receiver socket of the mobile phone through the interface box.

The noise suppression circuit is composed of a three-state buffer integrated circuit, and its input end is connected with the output end of the sound amplifier of the hands-free handset host.

The interface box further includes an earphone jack connected to the interface plug.

The utility model has the advantages of:

1. Since there is an interface plug on the main body of the hands-free handset, it can be plugged with interface boxes of different wiring types. When the user changes the mobile phone, he only needs to purchase or replace the interface box, which is more economical;

2. Since the host of the hands-free handset is provided with a noise suppression circuit, it can filter the echo signal fed back through the speaker of the hands-free handset, thereby improving the communication quality of the hands-free handset.

Hereinafter, an embodiment is given to describe in detail the structure, function and features of the present utility model in conjunction with the accompanying drawings.

Fig. 1 is the exterior view of the utility model;

Fig. 2 is the overall circuit block diagram of the present utility model;

Fig. 3 is the host circuit diagram of the utility model;

FIG. 4 is a circuit diagram of an embodiment of the interface box of the present invention.

As shown in Figure 1, the appearance of the hands-free handset of the present utility model is similar to that of a conventional hands-free handset. The hands-free main unit 10 at the seat 50 rear, one can obtain the power supply in the car and for the cigarette lighter plug 60 that the hands-free main unit 10 uses, two microphones M1 and the loudspeaker 12 plugged with the hands-free main unit 10 respectively, one The interface box 70 that can connect the mobile phone 30 to the hands-free main unit 10 through the interface plug 80 and the adapter 81, and an external earphone 71 that can be plugged into the earphone jack 73 of the interface box 70.

And the feature of the present utility model is: this hands-free handset main frame 10 is a kind of general-purpose type, is designed with a general interface socket 11, and the interface box 70 that plugs with it then has multiple types to choose from, namely the The internal wiring method of the interface box 70 and the adapter 81 for plugging in with the mobile phone 30 have different changes due to different specifications or brands of mobile phones, so that the user only needs to purchase the interface box 70 corresponding to the type of mobile phone 30, It can be closely matched with the hands-free handset main unit 10, eliminating the trouble of having to replace the hands-free handset at the same time when replacing the mobile phone. In addition, the microphone circuit inside the hands-free main unit 10 is provided with a device for eliminating the hands-free handset echo. Noise suppression circuit to improve communication quality.

The structure of the hands-free handset of the present utility model is shown in the block diagram of Figure 2, the hands-free handset host 10 includes an interface box 70 that can be connected with the mobile phone 30, a charging circuit 16, a sound amplifier 14, and a noise suppression circuit 13. A microphone M1 and a speaker 12 . The microphone M1 is connected in series with the noise suppression circuit 13, and then the output end of the noise suppression circuit 13 is connected in series with the interface box 70 to be connected with the sound input end of the mobile phone 30 to achieve the effect of eliminating echo; and the sound output end of the mobile phone 30 is connected in series Interface box 70, then connect sound amplifier 14, be connected to loudspeaker 12 at last, obtain the loudspeaker effect of hands-free receiver; Charging circuit 16 sends the required rated charging voltage of mobile phone 30, and its charging output end connects interface box 70, connects again To the charging terminal of the mobile phone 30, therefore, the signal of the call enters from the microphone M1, passes through the noise suppression circuit 13, and then is sent to the mobile phone 30 after being adjusted by the wiring of the interface box 70, and the mobile phone 30 outputs The audio signal is also transferred through the interface box 70, after the level amplification and power amplification are carried out through the audio amplifier 14, and then broadcast by the speaker 12, the mobile phone 30 can be given the effect of hands-free communication.

And the utility model is characterized in that: the interface box 70 which is arranged between the mobile phone 30 and the hands-free receiver main unit 10, the main purpose is to make it applicable to mobile phones of different specifications or brands and models, because the utility model is configured with A variety of interface boxes 70 that can be used with different mobile phones can be easily matched with various mobile phones by selecting the corresponding interface boxes. Therefore, when users change mobile phones, they only need to replace or purchase low-cost interface boxes. It is more economical to replace the entire microphone, and the noise suppression circuit 13 connected to the microphone M1 can eliminate noise and improve communication quality.

The detailed circuit of the hands-free handset host 10 and the interface box 70 is as shown in Figures 3 and 4, the lower left corner of Figure 3 is a universal interface socket 11 that can be plugged with the interface box 70 of Figure 4, its 8th pin and 10th pin The XMIC and XEAR of the pin are respectively connected to the microphone socket 133 in the lower right corner of the drawing and the sound amplifier 14 marked with a dotted frame in the center of the drawing. The sound amplifier 14 is composed of an analog sound amplification integrated circuit 141 (the model is TDA1905) and The resistors and capacitors connected to the peripheral positions are formed. The XEAR signal sent by the interface socket 11 is connected to a volume knob 15, and then connected to the input pin IN of the analog sound amplification integrated circuit 141, and the output pin of the analog sound amplification integrated circuit 141. OP is connected to the speaker socket 142 in the upper right corner of the drawing, and the microphone socket 133 in the lower right corner of the drawing is connected to the C4 output pin of the tri-state buffer integrated circuit 131 (model is MC14503B) in the noise suppression circuit 13. Buffer integrated circuit 131 is made up of multiple groups of tri-state buffers inside, and the input pin DIS4 of tri-state buffer integrated circuit 131 is connected with the collector of a transistor 132, and the base of transistor 132 is connected to the output terminal of aforementioned sound amplifier 14, so can Through the amplified output signal of the sound amplifier 14, the transistor 132 is turned on and off accordingly and the signal of the microphone socket 133 is blocked in a timely manner to eliminate the echo phenomenon. In the upper left corner of Fig. 3, a pulse width of a model TL594 is used. The modulation integrated circuit 161 and a power transistor 162 form a constant voltage and constant current type charging circuit 16, the output terminal C1 of the pulse width modulation integrated circuit 161 is connected to the base of the transistor 162, and the other terminals are connected to the feedback resistor or The ratio resistor is connected, the emitter input terminal of the transistor 162 is connected to the power supply V+, and the output terminal of the transistor 162 is connected to the interface socket 11 for charging the mobile phone.

FIG. 4 only describes the interface box 70 of one wiring type. Since the difference between different interface boxes 70 is only in the wiring pin positions and connector specifications, no individual description is given. In this example, it is composed of an interface connector 80 that can be plugged into the interface socket 11 of FIG. 3 , an adapter 81 that can be plugged into a mobile phone, and an earphone jack 73. It is formed by connecting wires, resistors and capacitors to form a signal transfer. Each contact point of the earphone jack 73 is connected to the interface plug 80 for receiving the audio signal sent by the hands-free handset host, and different interface boxes There are only changes in the adapter 81 and wiring.

Claims (3)

1. A hands-free handset for a mobile phone for a vehicle, comprising a mobile phone holder, a hands-free receiver set behind the holder, a microphone and a speaker plugged into the hands-free receiver, the hands-free receiver is provided with an interface socket, Sound amplifier and charging circuit, characterized in that: An interface box is set between the hands-free socket of the mobile phone and the interface socket of the hands-free main unit. The interface box is composed of an interface plug that can be plugged into the interface socket and an adapter that can be plugged into the hands-free socket of the mobile phone. , the interface plug and the adapter are connected by wiring, resistors and capacitors; A noise suppression circuit is set in the hands-free handset host, which is composed of a buffer and connected to a microphone. The output end of the noise suppression circuit is transferred to the hands-free handset socket of the mobile phone through the interface box. 2. The hands-free handset for a mobile phone for a vehicle according to claim 1, wherein the noise suppression circuit is composed of a three-state buffer integrated circuit, and its input end is connected to the output end of the sound amplifier of the hands-free handset host. 3. The hands-free handset for a mobile phone for a vehicle according to claim 1, wherein the interface box further includes an earphone jack, and the earphone jack is connected to the interface plug.

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